Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
Topic:Biochemistry
The study of biochemistry in horses encompasses the chemical processes and substances that occur within equine organisms. This field investigates the molecular interactions and pathways that are fundamental to horse physiology, including metabolism, enzyme activity, and genetic expression. Key areas of interest include the examination of metabolic disorders, nutrient absorption, and the biochemical basis of muscle function and energy production. Researchers utilize biochemical analysis to understand health and disease mechanisms in horses, contributing to the development of diagnostic tools and therapeutic strategies. This page gathers peer-reviewed studies and scholarly articles that explore various biochemical processes and their implications for equine health and performance.
Generation and characterization of leukemia inhibitory factor-dependent equine induced pluripotent stem cells from adult dermal fibroblasts. In this study we have reprogrammed dermal fibroblasts from an adult female horse into equine induced pluripotent stem cells (equiPSCs). These equiPSCs are dependent only on leukemia inhibitory factor (LIF), placing them in striking contrast to previously derived equiPSCs that have been shown to be co-dependent on both LIF and basic fibroblast growth factor (bFGF). These equiPSCs have a normal karyotype and have been maintained beyond 60 passages. They possess alkaline phosphatase activity and express eqNANOG, eqOCT4, and eqTERT mRNA. Immunocytochemistry confirmed that they produce NANOG, REX1,...
Exercise influences circadian gene expression in equine skeletal muscle. Circadian rhythms are endogenously generated 24-h oscillations that coordinate numerous aspects of mammalian physiology, metabolism and behaviour. The existence of a molecular circadian clock in equine skeletal muscle has previously been demonstrated. This study investigates how the circadian 24-h expression of exercise-relevant genes in skeletal muscle is influenced by a regular exercise regime. Mid-gluteal, percutaneous muscle biopsies were obtained over a 24-h period from six Thoroughbred mares before and after an 8-week exercise programme. Real-time qPCR assays were used to assess the expr...
Effect of osmotic stress on the expression of TRPV4 and BKCa channels and possible interaction with ERK1/2 and p38 in cultured equine chondrocytes. The metabolic activity of articular chondrocytes is influenced by osmotic alterations that occur in articular cartilage secondary to mechanical load. The mechanisms that sense and transduce mechanical signals from cell swelling and initiate volume regulation are poorly understood. The purpose of this study was to investigate how the expression of two putative osmolyte channels [transient receptor potential vanilloid 4 (TRPV4) and large-conductance Ca(2+)-activated K(+) (BKCa)] in chondrocytes is modulated in different osmotic conditions and to examine a potential role for MAPKs in this process...
Lidocaine effect on flotillin-2 distribution in detergent-resistant membranes of equine jejunal smooth muscle in vitro. Lidocaine is the most commonly chosen prokinetic for treating postoperative ileus in horses, a motility disorder associated with ischaemia-reperfusion injury of intestinal tissues. Despite the frequent use of lidocaine, the mechanism underlying its prokinetic effects is still unclear. Previous studies suggested that lidocaine altered cell membrane characteristics of smooth muscle cells. Therefore, the present study aimed to elucidate effects of lidocaine administration on characteristics of detergent-resistant membranes in equine jejunal smooth muscle. Lidocaine administration caused significa...
Effects of steroids on the morphology and proliferation of canine and equine mesenchymal stem cells of adipose origin – in vitro research. Disorders of the locomotive system, especially those occurring due to degenerative changes of the joints, are serious problems in daily veterinary medical practice. Steroid injections are the main way of treating these disorders. However, this approach brings usually only temporary effects of pain relief, and may cause many side effects. Alternative therapies focus on regeneration of damaged tissue using adult mesenchymal stem cells (MSCs). Since 2002, the great plasticity and immunomodulatory properties of MSCs isolated from adipose tissue (AdMSCs) have been used successfully in the treatment...
Cholinesterase inhibitory triterpenoids from the bark of Garcinia hombroniana. Context: Garcinia hombroniana Pierre, known as manggis hutan in Malaysia is a rich source of xanthones and benzophenones. Objective: This study was aimed to isolate and characterize potential cholinesterase inhibitors from the extracts of G. hombroniana bark and investigate their interactions with the enzymes. Methods: The dichloromethane extract afforded five triterpenoids which were characterized by NMR and mass spectral techniques. Cholinesterase inhibitory assay and molecular docking were performed to get insight of the inhibitory activity and molecular interactions of the compounds. The c...
The analysis of pergolide residues in horse plasma by LC with fluorescence detection. Pergolide is used to treat pituitary pars intermedia dysfunction (equine Cushing's Disease), a neurodegenerative condition associated with loss of dopaminergic inhibition of the pituitary in horses. After oral administration, only low concentrations of the drug are achieved in plasma, making drug detection and quantification difficult. While direct analysis of plasma using sensitive MS/MS techniques is possible, dirty plasma samples and mobile phase buffers can cause instrumentation to become rapidly incapacitated. A method using LC with fluorescence detection was developed for pergolide analy...
Protein catabolism and high lipid metabolism associated with long-distance exercise are revealed by plasma NMR metabolomics in endurance horses. During long distance endurance races, horses undergo high physiological and metabolic stresses. The adaptation processes involve the modulation of the energetic pathways in order to meet the energy demand. The aims were to evaluate the effects of long endurance exercise on the plasma metabolomic profiles and to investigate the relationships with the individual horse performances. The metabolomic profiles of the horses were analyzed using the non-dedicated methodology, NMR spectroscopy and statistical multivariate analysis. The advantage of this method is to investigate several metabolomic path...
Structural and biochemical insights into the V/I505T mutation found in the EIAV gp45 vaccine strain. The equine infectious anemia virus (EIAV) is a lentivirus of the Retrovirus family, which causes persistent infection in horses often characterized by recurrent episodes of high fever. It has a similar morphology and life cycle to the human immunodeficiency virus (HIV). Its transmembrane glycoprotein, gp45 (analogous to gp41 in HIV), mediates membrane fusion during the infection. However, the post-fusion conformation of EIAV gp45 has not yet been determined. EIAV is the first member of the lentiviruses for which an effective vaccine has been successfully developed. The attenuated vaccine strai...
A comparative study of free oligosaccharides in the milk of domestic animals. The present study was conducted to obtain a comprehensive overview of oligosaccharides present in the milk of a variety of important domestic animals including cows, goats, sheep, pigs, horses and dromedary camels. Using an analytical workflow that included ultra-performance liquid chromatography-hydrophilic interaction liquid chromatography with fluorescence detection coupled to quadrupole time-of-flight MS, detailed oligosaccharide libraries were established. The partial or full characterisation of the neutral/fucosylated, phosphorylated and sialylated structures was facilitated by sequencin...
Transferrin receptor expression in serum exosomes as a marker of regenerative anaemia in the horse. Evaluation of erythrocyte regeneration in horses is challenging, as they do not release reticulocytes into the peripheral blood. This study investigated transferrin receptor 1 (TfR1) expression in exosomes as a noninvasive method of characterising the regenerative response in anaemic horses. Objective: To quantify TfR1 in ultraprecipitate of serum in horses before and after phlebotomy-induced anaemia, and to identify exosomes as the source of TfR1. The hypothesis was that serum exosomal TfR1 expression would increase during a regenerative response. Methods: Experimental model of anaemia. Metho...
The expression and activity of 5-LOX in the large intestine of horses harbouring encysted cyathostomin larvae. Leukotrienes are products of the arachidonic acid metabolism and act as potent inflammatory mediators modulating the immune response and various physiological processes. This study evaluated the expression and activity of 5-lipoxygenase (5-LOX), the enzyme that catalyzes the first two steps in the biosynthesis of leukotrienes, in horses infected by larval cyathostomins. Tissue samples from dorsal and ventral colon, and from the cecum were collected from 16 horses slaughtered for human consumption. Samples were analyzed to estimate the burdens of encysted cyathostomin larvae and adult luminal s...
Pharmacological characterization of muscarinic receptors in the contractions of isolated bronchi in the horse. We investigated the effects of nonselective muscarinic antagonist (atropine) and of selective muscarinic subtype 1 (M1), 2 (M2), 3 (M3) antagonists (VU0255035, methoctramine, pFHHSiD, respectively) on the contractions evoked by electrical field stimulation (EFS) or by exogenous ACh in isolated horse bronchial muscle. Atropine completely inhibited neurogenic contractions in a concentration-dependent fashion, whereas selective muscarinic antagonists induced relevant modifications only at the highest concentration tested. Experiments with selective muscarinic antagonists in combination showed tha...
Expression and regulation of facilitative glucose transporters in equine insulin-sensitive tissue: from physiology to pathology. Glucose uptake is the rate-limiting step in glucose utilization in mammalians and is tightly regulated by a family of specialized proteins, called the facilitated glucose transporters (GLUTs/SLC2). GLUT4, the major isoform in insulin-responsive tissue, translocates from an intracellular pool to the cell surface and as such determines insulin-stimulated glucose uptake. However, despite intensive research over 50 years, the insulin-dependent and -independent pathways that mediate GLUT4 translocation are not fully elucidated in any species. Insulin resistance (IR) is one of the hallmarks of equin...
Stallion spermatozoa: putative target of estrogens; presence of the estrogen receptors ESR1, ESR2 and identification of the estrogen-membrane receptor GPER. Among mammals, the stallion produces the largest amount of testicular estrogens. These steroid hormones are produced mainly by Leydig and Sertoli cells in the testis and also in the epididymis. Their role in horse testicular physiology and their ability to act on spermatozoa are still unknown. In order to determine if spermatozoa are targets for estrogens, the presence of estrogen receptors in mature ejaculated spermatozoa has been investigated. The presence of a single isoform of ESR1 (66kDa) and ESR2 (61kDa) was found by Western-blot analysis in samples from seven stallions. Confocal analysi...
Analytical performance of a dry chemistry analyzer designed for in-clinic use. The Heska Dri-Chem 4000 uses dry slide technology to evaluate serum or plasma. No previous independent performance evaluation is published to the authors' knowledge. Objective: The objectives were to (1) characterize analytical performance of a Dri-Chem 4000 by measuring precision and bias, (2) compare analytical performance of that Dri-Chem 4000 unit with a predetermined quality requirement, and (3) determine whether statistical QC of the Dri-Chem 4000 is possible using the 13s control rule. Methods: Sixteen analytes were measured using plasma from dogs, cats, and horses. Coefficient of varia...
Evaluation of health status of horses immunized with snake venom and montanide adjuvants, IMS 3012 (nanoparticle), ISA 206 and ISA 35 (emulsion based) during polyvalent snake antivenom production: hematological and biochemical assessment. Several biochemical and hematological changes in horses are observed during production of snake antivenom. Although conventional adjuvants like Freund's (Complete and Incomplete) are good immunopotentiators, they produce considerable local reactions in animals. Variety of commercial adjuvants, like montanide adjuvants, having high immunopotentiation and showing lesser side effects are available. The prime objective during antivenom production is to strike a balance between safety of immunized horses and efficacy of the product. In our earlier work, efficacy of montanide group of adjuvants in a...
Doping control analysis of filgrastim in equine plasma and its application to a co-administration study of filgrastim and recombinant human erythropoietin in the horse. Granulocyte colony-stimulating factor (G-CSF) is a hematopoietic growth factor regulating granulopoiesis. The recombinant human granulocyte colony-stimulating factor (rhG-CSF) is widely used for the treatment of granulopenia in humans. Filgrastim is a rhG-CSF analogue and is marketed under various brand names, including Neupogen(®) (Amgen), Imumax(®) (Abbott Laboratories), Neukine(®) (Intas Biopharmaceuticals) and others. It is banned in both human and equine sports owing to its potential for misuse. In order to control the abuse of filgrastim in equine sports, a method to identify unequivo...
Factors influencing total carbon dioxide concentrations in plasma of thoroughbred and standardbred racehorses. Horse racing authorities impose a limit on the concentration of plasma 'total carbon dioxide' (TCO2), typically 36 mM with action taken above 37 mM, as measured by an electrochemical gas analyzer. It is of interest to understand the distribution of TCO2 in a 'normal' population of racehorses and determine probabilities of members of this population exceeding these current regulatory and action limits. TCO2 levels in equine plasma samples have been modelled for 12 months (2011-2012) of thoroughbred (3076 measurements) and standardbred (3788 measurements) data in Australia. The two populations h...
Gross placental morphology and foal serum biochemistry as predictors of foal health. The aim of this study was to verify if changes in blood glucose, creatinine, urea, and fibrinogen concentrations evaluated at birth reflect gross placenta abnormalities, and are useful to identify foals that suffered from placental dysfunction. A total of 92 mares were included in the present study: 68 delivered healthy foals and they were included in group 1; 24 delivered sick foals and they were included in group 2. In group 2, foals' clinical diagnoses included perinatal asphyxia syndrome (PAS; n = 20) and prematurity and/or dysmaturity (n = 4). The proportion of sick foals was greater when...
Variation in salivary and pancreatic alpha-amylase genes in Italian horse breeds. The dietary demand of the modern horse relies on high-cereal feeding and limited forage compared with natural grazing conditions, predisposing the horse to several important diseases. Salivary and pancreatic alpha-amylases (coded by AMY1 and AMY2 genes, respectively) play a crucial role in carbohydrate digestion in nonruminants, but little is known about these 2 genes in the horse. Aim of this work has been to distinguish genomic sequences of horse AMY1 and AMY2 genes and to analyze any polymorphisms in breeds historically characterized by marked differences in nutritional management. A single...
Pregnancy without progesterone in horses defines a second endogenous biopotent progesterone receptor agonist, 5α-dihydroprogesterone. One of the most widely accepted axioms of mammalian reproductive biology is that pregnancy requires the (sole) support of progesterone, acting in large measure through nuclear progesterone receptors (PRs) in uterine and cervical tissues, without which pregnancy cannot be established or maintained. However, mares lack detectable progesterone in the latter half of pregnancy. Instead of progesterone, several (mainly 5α-reduced) pregnanes are elevated and have long been speculated to provide progestational support in lieu of progesterone itself. To the authors' knowledge, evidence for the bioacti...
Anaerobic digestion of horse dung mixed with different bedding materials in an upflow solid-state (UASS) reactor at mesophilic conditions. Aim of this study was to investigate the use of upflow anaerobic solid-state (UASS) digestion for treating horse manure. Biochemical methane potential (BMP) tests conducted for varying mixtures of dung (hay and silage feed) and bedding material (wheat straw, flax, hemp, wood chips) showed that straw mixed with hay horse dung has the highest potential of [Formula: see text] . Continuous mesophilic digestion was conducted for 238 days using a single-stage UASS reactor (27 L) and a two-stage UASS system with an anaerobic filter (AF, 21 L). Increasing the organic loading rate (OLR) from 2.5 to 4.5...
Hypothalamic distribution, adenohypophyseal receptor expression, and ligand functionality of RFamide-related peptide 3 in the mare during the breeding and nonbreeding seasons. RFamide-related peptide 3 (RFRP3), the mammalian homologue of avian gonadotropin-inhibitory hormone, has been shown to negatively regulate the secretion of LH and may contribute to reproductive seasonality in some species. Herein, we examined the presence and potential role of the RFRP3-signaling system in regulating LH secretion in the mare during the breeding and nonbreeding seasons. Hypothalamic NPVF mRNA (the precursor mRNA for RFRP3) was detected at the level of the dorsomedial nucleus and paraventricular nucleus, but expression did not change with season. A greater number of RFRP3-expres...
Interleukin-1β inhibits synthesis of 5-lipooxygenase in lipopolysaccharide-stimulated equine whole blood. Interleukin-1β (IL-1β) is a pro-inflammatory cytokine. It induces the synthesis of prostaglandin E2 (PGE2) catalyzed by cyclooxygenase (COX) and microsomal prostaglandin E synthase (m-PGES). Besides its pro-inflammatory properties, PGE2 also exhibits anti-inflammatory properties by inhibiting synthesis of 5-lipooxygenase (5-LO) products which are in themselves, pro-inflammatory mediators. Thus, inhibition of 5-LO products is beneficial in regulating immune-responses and pro-inflammatory processes. To investigate the hypothesis that IL-1β is responsible for the increase in the synthesis of P...
Development and validation of a gas chromatography-flame ionization detection method for quantifying sucrose in equine serum. A simple and accurate method for quantifying sucrose in equine serum that can be applied to sucrose permeability testing in the horse was developed and validated using gas chromatography with flame ionization detection. The assay provided an acceptable degree of linearity, accuracy, and precision at concentrations of sucrose as low as 2.34 μmol/l and as high as 20.45 μmol/l. Percentage recovery of sucrose from serum ranged from 89% to 102%; repeatability and intermediate precision (relative standard deviation) ranged from 3.6% to 6.7% and 4.1% to 9.3%, respectively. The limit of detection wa...
Cholesterol-loaded-cyclodextrins improve the post-thaw quality of stallion sperm. An unacceptable proportion of stallion sperm do not survive the freeze-thaw process. The hypothesis of this study was that adding cholesterol to a stallion semen extender would stabilise the sperm membrane, resulting in an improved post-thaw semen quality in terms of increased sperm viability, membrane integrity and fluidity, and reduced oxidative stress. Semen was collected from three stallions and diluted in four extenders: TALP; TALP+0.75mg methyl-β-cyclodextrin-cholesterol (MβCD)/mL (MβCD0.75); TALP+1.5mg MβCD-cholesterol/mL (MβCD1.5); and Equipro. Following 15min incubation, samples ...
Expression of aldo-keto reductase 1C23 in the equine corpus luteum in different luteal phases. Regression of the corpus luteum (CL) is characterized by a decay in progesterone (P4) production (functional luteolysis) and disappearance of luteal tissues (structural luteolysis). In mares, structural luteolysis is thought to be caused by apoptosis of luteal cells, but functional luteolysis is poorly understood. 20α-hydroxysteroid dehydrogenase (20α-HSD) catabolizes P4 into its biologically inactive form, 20α-hydroxyprogesterone (20α-OHP). In mares, aldo-keto reductase (AKR) 1C23, which is a member of the AKR superfamily, has 20α-HSD activity. To clarify whether AKR1C23 is associated wi...
Alterations in sclerostin protein in lesions of equine osteochondrosis. Osteochondrosis (OC) is a common and clinically important joint disease that occurs in many species, including humans, pigs, chickens and horses. It has been described as a focal failure of endochondral ossification (EO), but no cellular/molecular mechanisms are fully described that explain the cause of this condition. Recently a Wnt signalling inhibitor, sclerostin, has been described in osteoarthritic cartilage, where it has been proposed to protect damaged cartilage from degradation. Cartilage degradation is a key event in EO, thus, abnormalities of sclerostin in growth cartilage could, pot...
Concentration, activity and biochemical characterization of myeloperoxidase in fresh and post-thaw equine semen and their implication on freezability. Myeloperoxidase (MPO) is a pro-oxidant enzyme associated with decreased motility in thawed equine semen. This study aimed to describe MPO concentration, activity and subunits in raw and thawed semen and to correlate these data with motilities in raw and thawed semen. Semen samples from five stallions were collected four times. Motilities were assessed in raw and thawed semen. MPO assays were performed in raw seminal plasma, raw sperm-rich pellet and thawed semen. Total and active MPO concentrations were, respectively, assayed by enzyme-linked immunosorbent assay and specific immunological extr...
